Most business and financial institutions use computer systems that exploit the power of computer networking. By networking, individual computers can effectively increase their storage and processing ability, as well as gain access to processed data and live data streams. Such networks range in size from a few computers on a local area network (LAN) in a single office to hundreds or perhaps even thousands of computers spanning many offices and locations. These networks range in size from those confined to a single organization (Intranets) to those built on the global Internet.
To achieve the best utilization of the networked environment, organizations employ complex suites of software. Typically these suites are a mix of commercial software packages, customized commercial software, and software written entirely in house. For example, in a financial trading environment, traders can use desktop computers to view current market prices, to analyze various markets and instruments, and to buy and sell financial instruments. Teams of computer specialists including systems analysts and computer programmers write, integrate, and manage the systems of computer programs that create a financial institution's trading software environment.
These complex suites of software need to be periodically updated or replaced. This need may arise from changed business practices, or the availability of faster software packages or packages with new enhanced features. Any benefits that can be obtained from the installation of new software must be balanced against the risk of making changes on an otherwise properly operating network. Such changes can cause intermittent or event total network failure. Network failures can cause organizations to suffer large financial losses, such as lost trades in a financial instrument trading environment.
Rather then risk catastrophic network failure during testing, many institutions invest in relatively large networks of computers to create a “safe” simulation environment for testing complex software systems as thoroughly as practical. Networks comprising tens or hundreds of computers, including servers and client terminals, are often dedicated solely to testing complex software. Such systems can cost tens of millions of dollars and approximate or match the size and resources of some of an organization's production network systems.
While relatively safe, testing on the simulation network is not efficient. This is because each new software package is typically tested one at a time. Test runs are often paused for debugging and software re-writes. During the pause times, the test network remains idle. It is not practical to terminate a particular test and restart the system for other tasks because then all of the test time before termination would need to be repeated. The problem is that there is currently no process for suspending an entire network of computers to allow it to temporarily stand in for another entirely different network software environment, or to temporarily take over the software environment of an operational network in an emergency.
What is needed is a method to suspend a complex software testing environment in an orderly way so as to completely free the test network to run another test, or even to momentarily commandeer the test network to run a production processing environment in the event of a necessary shutdown or unanticipated failure of an equivalent production system, with the ability to seamlessly resume the original testing environment after the network resources have been returned.